Mac: Use a cache for ScreenMac::GetDisplayForScreen().

Mac: Use a cache for ScreenMac::GetDisplayForScreen().

Performance traces on the associated bugs turn up a lot of time spent in
display::screen_mac::GetDisplayForScreen(). It does a lot of work, and
calls some expensive AppKit and CoreGraphics methods. It's currently
invoked multiple times during a window resize.

GetDisplayNearestWindow would also invoke -[NSWindow
_bestScreenBySpaceAssignmentOrGeometry] which does some synchronous
messaging with the window server process, adding significant latency.

ScreenMac already maintains a std::vector<Display>, but
GetDisplayForScreen() does not use it.

Use it.

Optimize GetDisplayNearestWindow for the case of a single display.

BUG=666556, 665280
Committed: https://crrev.com/7330ed4e42141778cb25604dd4949471f034a38f
Cr-Commit-Position: refs/heads/master@{#433463}

[tapted, 2016-11-18 04:11:13]

The CQ bit was checked by tapted@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-11-18 04:11:49]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[tapted, 2016-11-18 04:30:08]

Description was changed from

==========
Mac: Use a cache for ScreenMac::GetDisplayForScreen().

ScreenMac already maintains a std::vector<Display>, but GetDisplayForScreen
(and all the things that use it, e.g. GetDisplayNearestWindow) do not
use it.

Use it.

BUG=666556, 665280
==========

to

==========
Mac: Use a cache for ScreenMac::GetDisplayForScreen().

Performance traces on the associated bugs turn up a lot of time spent in
display::screen_mac::GetDisplayForScreen(). It does a lot of work, and
calls some expensive AppKit and CoreGraphics methods. It's currently
invoked multiple times during a window resize.

GetDisplayNearestWindow would also invoke -[NSWindow
_bestScreenBySpaceAssignmentOrGeometry] which does some synchronous
messaging with the window server process, adding significant latency.

ScreenMac already maintains a std::vector<Display>, but
GetDisplayForScreen() does not use it.

Use it.

Optimize GetDisplayNearestWindow for the case of a single display.

BUG=666556, 665280
==========

[tapted, 2016-11-18 04:30:08]

tapted@chromium.org changed reviewers:
+ ccameron@chromium.org

[tapted, 2016-11-18 04:33:13]

The CQ bit was checked by tapted@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-11-18 04:33:59]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-11-18 05:18:42]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-11-18 05:18:43]

Dry run: This issue passed the CQ dry run.

[tapted, 2016-11-18 07:42:06]

Hi Chris - WDYT?

[ccameron, 2016-11-18 17:55:51]

Yes, lgtm.

[tapted, 2016-11-20 22:56:09]

The CQ bit was checked by tapted@chromium.org

[commit-bot: I haz the power, 2016-11-20 22:56:14]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-11-20 23:48:58]

CQ is committing da patch.

Bot data: {"patchset_id": 40001, "attempt_start_ts": 1479682569076120,
"parent_rev": ["e5f9d7fd216ee3affff4d4991900af96f35d8322", null], "commit_rev":
["101abd5dea38141fdd82bd50d15bc263ca7ebcdc", null]}

[commit-bot: I haz the power, 2016-11-20 23:49:22]

Description was changed from

==========
Mac: Use a cache for ScreenMac::GetDisplayForScreen().

Performance traces on the associated bugs turn up a lot of time spent in
display::screen_mac::GetDisplayForScreen(). It does a lot of work, and
calls some expensive AppKit and CoreGraphics methods. It's currently
invoked multiple times during a window resize.

GetDisplayNearestWindow would also invoke -[NSWindow
_bestScreenBySpaceAssignmentOrGeometry] which does some synchronous
messaging with the window server process, adding significant latency.

ScreenMac already maintains a std::vector<Display>, but
GetDisplayForScreen() does not use it.

Use it.

Optimize GetDisplayNearestWindow for the case of a single display.

BUG=666556, 665280
==========

to

==========
Mac: Use a cache for ScreenMac::GetDisplayForScreen().

Performance traces on the associated bugs turn up a lot of time spent in
display::screen_mac::GetDisplayForScreen(). It does a lot of work, and
calls some expensive AppKit and CoreGraphics methods. It's currently
invoked multiple times during a window resize.

GetDisplayNearestWindow would also invoke -[NSWindow
_bestScreenBySpaceAssignmentOrGeometry] which does some synchronous
messaging with the window server process, adding significant latency.

ScreenMac already maintains a std::vector<Display>, but
GetDisplayForScreen() does not use it.

Use it.

Optimize GetDisplayNearestWindow for the case of a single display.

BUG=666556, 665280
==========

[commit-bot: I haz the power, 2016-11-20 23:49:23]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2016-11-20 23:51:59]

Description was changed from

==========
Mac: Use a cache for ScreenMac::GetDisplayForScreen().

Performance traces on the associated bugs turn up a lot of time spent in
display::screen_mac::GetDisplayForScreen(). It does a lot of work, and
calls some expensive AppKit and CoreGraphics methods. It's currently
invoked multiple times during a window resize.

GetDisplayNearestWindow would also invoke -[NSWindow
_bestScreenBySpaceAssignmentOrGeometry] which does some synchronous
messaging with the window server process, adding significant latency.

ScreenMac already maintains a std::vector<Display>, but
GetDisplayForScreen() does not use it.

Use it.

Optimize GetDisplayNearestWindow for the case of a single display.

BUG=666556, 665280
==========

to

==========
Mac: Use a cache for ScreenMac::GetDisplayForScreen().

Performance traces on the associated bugs turn up a lot of time spent in
display::screen_mac::GetDisplayForScreen(). It does a lot of work, and
calls some expensive AppKit and CoreGraphics methods. It's currently
invoked multiple times during a window resize.

GetDisplayNearestWindow would also invoke -[NSWindow
_bestScreenBySpaceAssignmentOrGeometry] which does some synchronous
messaging with the window server process, adding significant latency.

ScreenMac already maintains a std::vector<Display>, but
GetDisplayForScreen() does not use it.

Use it.

Optimize GetDisplayNearestWindow for the case of a single display.

BUG=666556, 665280

Committed: https://crrev.com/7330ed4e42141778cb25604dd4949471f034a38f
Cr-Commit-Position: refs/heads/master@{#433463}
==========

[commit-bot: I haz the power, 2016-11-20 23:52:00]

Patchset 3 (id:??) landed as
https://crrev.com/7330ed4e42141778cb25604dd4949471f034a38f
Cr-Commit-Position: refs/heads/master@{#433463}